There are many resources available for finding grants.  Listed below are databases and web resources to assist you in finding the information you need:

GuideStar - Connecting people with non-profit information.

GrantSmart - Contains 555,114 tax returns filed by 100,122 private foundations and charitable trusts. - Allows organizations to electronically find and apply for more that $400 billion in Federal grants.

More web resources for grantwriters: